Sealing glass for laser glass

ABSTRACT

A sealing glass for laser glass produced by adding V2O5 0-18 mol.%, Fe2O3 0-18 mol.%, (V2O5+Fe2O3 5-18 mol.%), Co2O3 0-6 mol.% and NiO 0-7 mol.% to a balancing amount of a base glass composed of P2O5 70-30 mol.%, B2O3 0-15 mol.%, Al2O3 0-5 mol.%, (P2O5+B2O3+Al2O3 30-70 mol.%), PbO 0-55 mol.%, Tl2O 0-55 mol.%, ZnO 5-50 mol.%, (PbO+Tl2O 20-55 mol.%; PbO+Tl2O+ZnO 25-60 mol.%) and BaO 0-10 mol.%.

United States Patent Asahara et al.

SEALING GLASS FOR LASER GLASS Inventors: Yoshiyuki Asahara, Kawasaki;

Tetsuro Izumitani, Hino, both of Japan Hoya Glass Works, Limited, Tokyo, Japan Filed: July 30, 1973 App]. No.: 383,743

Assignee'.

Foreign Application Priority Data Oct. 9, 1972 Japan 47-101367 US. Cl. 106/47 Q Int. Cl. CO3c 3/12; CO3c 3/16; CO3c 3/30 Field of Search..... 106/47 Q, 47 R; 117/124 A,

References Cited UNITED STATES PATENTS 4/1942 Tillyer et al 106/47 R LIGHT TRANSMITTING RATIO Primary Examiner-Winston A. Douglas Assistant Examiner-Mark Bell Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn and Macpeak [57 ABSTRACT A sealing glass for laser glass produced by adding V 0-18 mol.%, Fe O 0-18 mol.%, (v O -l-Fe O 5-18 mol.%), C0 0 0-6 mol.% and MO 0-7 mol.7r to a balancing amount of a base glass composed of P 0 70 30 mo1.%, B 0 O- mol.%, A1 0 0-5 mol.%, (P O +B2O +AI O 3070 mol.%), PbO 0-55 mol. T1 0 0-55 mo1.%, ZnO 5-50 mol.%, (PbO+Tl O -55 mol.%; PbO+Tl O+ZnO -60 mol.7() and E210 010 mol.%.

3 Claims, 1 Drawing Figure l I I 1000 I I200 I300 I400 I500 WAVELENGTH (mu) SEALING GLASS FOR LASER GLASS BACKGROUND OF THE INVENTION 1. Field of the Invention that a P O -ZnO-Tl O glass and a P O -ZnO-PbO glass ,exhibit a low n value, a low melting point and an expansion coefficient almost equal to that of a laser glass, and are suitable for use as a sealing glass. These This invention relates to a' sealing glass for laser glass 'g containing 2 5 as the P y component have which has a low optical absorption coefficient and a low melting point and which is capable of absorbing infrared rays.

2. Description of the Prior Art Recently, it has been reported that laser glass discs can be covered with a sealing glass at their outer periphery to absorb light scattered by the inner wall of the discs and thereby improve the characteristics of the laser glass discs. Such a sealing glass is required to have an expansion coefficient equal to that of the laser glass and to be able to seal at a temperature below the transition temperature (Tg) of the laser glass. In addition, the sealing glass must have an absorption coefficient which prevents the reflection of light ofthe desired wavelength, and have an absorption curve to absorb the light scattered by the inner wall of the discs. For example, the sealing glass must absorb at least light of a 1.06 p. wavelength to prevent reflection of light bythe inner wall of ari Nd laser glass; preferably the sealing'glass, has an absorption coefficient higher than that of the normal laser glass (about 1.6) and the difference between the absorption coefficients is preferably smaller than 10% of the absorption coefficient of the laser glass. Further, the sealing glass must have a softening point at least 100C lower than the transition point of 3 the laser glassso as to not change the characteristics of the laser glass during sealing.

the further advantage that they are capable of containing large amounts of oxides of transition elements, e.g., V 0 or Fe O as infrared absorbing compounds.

BRIEF EXPLANATION OF ACCOMPANIED DRAWING The FIGURE shows the relationship between the wavelength of light and the transmission of the glass of this invention, in which curve 1 shows the relationship for glass specimen l1 and curve 2 shows the relation- .ship for glass specimen l5.

DETAILED DESCRIPTION OF THE INVENTION The glass of this invention for sealing a laser glass is produced by adding V 0 0-18 mol.%, Fe O 0-18 mol.%, (V O +Fe O 5-18 mol.%), C0 0 0-6 mol.% and MO 0-7 mol.% to a balancing amount of a base 2 glass (to make 100 mol.%) composed of P 0 70-30 0 and BaO 0-10 mol.%.

Table 1 shows several P O -PbO-ZnO glasses and their physical properties.

Table 1 Specimen Composition (mol.%) Expansion Transition Softening Absorption No. Coefficient Temp. Point Coefficient P 0 PbO ZnO (X 10* /C) (C). (C)

SUMMARY OF THE INVENTION Each expansion coefficient was measured in the temperature range of 100-200C; each absorption coefficient is that for the a line and was in the range of 1.60-1.75; and each softening point was in the range of 300-400C. These physical properties are suitable for sealing 'laser glass.

Table 2A shows several glass compositions according to this invention produced by adding the infrared absorbing compounds to the P 0 containing base glass,

This invention has been made based on the discovery and Table 2B gives their physical properties Table 2A Specimen Base Glass Composition (mol.%) Added Compounds(mol.%) Expansion No. Coefficient P 0 PbO T1 0 ZnO A1 0; V 0 Fe O (X l0"/C +BaO 5 6 11 64.4 13.9 13.9 2.2 11.1 96.0

Table 2A Continued Epecimen Base Glass Composition (mol.%) Added Compunds(mol.%) Expansion -10, Coefficient {P205 PbO Tl O ZnO A1203 V205 Fe O (X lO /C) z a l4 52.9 23.5 ll.8 ll.8 17.6 l5 48.0 40 l0 2 l5 99.7 l6 63 3O 5 2 l0 104 l7 48 5O 5 2 l0 I 18 l 8 48 30 l0 l0 2 l0 1 l4 i9 48 10 20 10 2 10 2O 48 40 10 2 10 "fipecimen 14 contains 8,0 1L8 mol.% instead of Al.,O

Table 2B ble and the absorption coefficient is undesirably in- 15 creased. On the other hand, if either the Tl O content Light Transmitting or the PbO content is not more than 10 mol.% the soft- Iipecimen Tg Sp Thickness n' t NO- (00 (no 600 mi 1000 ml (mm) e mg point of he resulting glass 1s too high to be useful as a low melting point glass. In a system containing l 400 420 2 4 0.52 ZnO, i.e., where the content of PbO, T1 0 and ZnO is 3?? g 8 not more than mol.%, if only PbO is added without 4 380 405 v adding T1 0 (the ZnO content is 15 mol.% and the PhD :28 G G content is not more than 10 mol.%), a high melting 400 420 2 3.5 point glass is obtained, and the resulting glass is not 8 425 450 9 21 0 57 2 useful. Thus, if PhD is used alone, a glass having a conl r i2; 5 tent of PbO not more than 10 mol.% [8 not useful since ll 437 467 a high melting point glass is obtained. If T1 0 is used 22 22% m alone, the same effect as in the above case is observed. l l4 430 If the ZnO content exceeds 50 mol.%, the softening F I 30 point of the resulting glass is too high to be useful as a 7 390 405 low melting point glass, whereas a ZnO content less l8 362 380 than 5 mol.% increases the absorption coefficient too I I much. The sum of the PbO, T1 0 and ZnO content According to the accompanying drawing showing light transmitting curve 1 for Specimen 11 and curve 2 for Specimen l5, sealing glass 11 does not transmit light of less than 1200 my in wavelength and the transmission ratio of glass specimen 15 is sharply reduced for light having a wavelength of about 1000 m/J-. The expansion coefficient of these glasses lies in the range of lOOiZO) X 10 /C, and the softening point lies in the range of 320-467C, which is suitable for sealing work carried out at 450-600C. In addition, the chemical durability of the glass is improved by the addition of the transition elements.

Some of the phosphate glasses of this invention containing both Fe O and C0 0 and/or NiO are useful as low melting point black glasses. Some examples thereof are shown in Table 3.

must be 60 mol.% or lower to make the resulting glass stable. If the content of PhD, T1 0 and ZnO is not more than 25 mol.%, the acid resistance is poor and the softening point is high.

If necessary, less than 10 mol.% of BaO may be added to the glass composition. The addition of BaO to the glass makes the glass stable, but it does not directly I influence the thermal properties, e.g., a, Tg, Sp (softening point), n etc.

An addition of more than 18 mol.% V 0 or of more than 18 mol.% Fe O increases the softening point of the glass and renders the resulting glass unstable. The sum of V 0 and Fe O must exceed 5 mol.% to obtain the infrared absorbing property.

The addition of more than 6 mol.% C0 0 or of more than 7 mol.% NiO, respectively, make the resulting Table 3 Specimen Base Glass (mol.%) Added Compounds (mol.%) Expansion Tg Sp Coefficient No. .P O PbO ZnO V 0 Fe O C0 0 NiO (X l0"/C) (C) (C) .22 5O 30 3O 10 5.8 86.2 430 455 l3 49.4 30.2 30.4 10.2 2.9 4.4 94.4 435 462 14 66.6 16.7 16.7 ll.l 3.l 2.0 91.7 415 440 The amount of each component in the sealing glass glass unstable.

is restricted in the ranges as described in the claims for the reasons set out below.

if the P 0 content in the glass exceeds 70 mol.%, the chemical durability of the latter is diminished, whereas if the P 0 content is reduced below 30 mol.% the resulting glass becomes unstable. Up to 15 mol.% of P 0 can be substituted for by 0l5 mol.% of B 0 or O-5 mol.% of Al O If the T1 0 content or the PbO content exceeds 55 mol.%, respectively, the resulting glass becomes unsta- The glass composition is formed into a frit and mixed with a suitable organic vehicle. This mixture is coated on the surface of the laser glass and heated thereon to seal the latter. The glass compositions are formed using standard techniques. For instance, with the material of Example 18, glass frits resulting from grinding glass pieces in a mortor for 30 minutes were dispersed into a mixed vehicle of amyl acetate and cellulose nitrate to form a paste-like material. The resulting paste-like material was applied to a surface of the glass and then left at 470C for 3 hours. As a result, a suitable sealing effeet was obtained, the thickness of the sealing layer being approximated to be about 200 t.

While this invention has been described with reference to particular embodiments thereof, it will be understood that the numerous modifications may be made by those skilled in the art without actually departingfrom the scope of the invention.

Therefore, the appended claims are intended to cover all such equivalent variations as coming within the true spirit and scope of this invention.

What is claimed is:

l. A sealing glass for laser glass produced by adding V 0-18 mol.%, Fe O 0-18 mol.%, (V O +Fe O 5-18 mol.%), C0 0 0-6 mol.% and NiO 0-7 mol.% to 

1. A SEALING GLASS FOR LASER GLASS PRODUCED BY ADDING V2O5 0-18 MOL.%, FE2O3 0-18 MOL.%, (V2O5+FE2O3 5-18 MOL.%), CO2O3 0-6 MOL.% AND NIO 0-7 MOL.% TO A BALANCING AMOUNT OF A BASE GLASS CONSISTING OF P2O5 70-30 MOL.%, B2O3 0-15 MOL.%, AL2O3 0-5 MOL.%, (P2O5+B2O3+AL2O3 30-70 MOL.%), PBO 0-55 MOL.%, TL2O 0-55 MOL.%, ZNO 5-50 MOL.%,
 2. A sealing glass for laser glass according to claim 1 which is produced by adding V2O5 in an amount of 5-18 mol.%.
 3. A sealing glass for the laser glass according to claim 1 which consists of: P2O5 45-50 mol.%, PbO 25-35 mol.%; Tl2O 5-15 mol.%; ZnO 5-15 mol.%; Al2O3 1-5 mol.%; V2O5 5-15 mol.%. 